Internal-cylinder grinder



May 31, 1927. v1,630,353

l.. D. PANGBORN ET AL 'l INTERNAL CYLINDER GRINDER Filed July l2, 1924ay ai, 1927- Patented LEO D; PANGBORN, ROGERS M. WARWICK, AND GEORGE H.MGKAY, or CHICAGO, ILLI- NoIs, AssIGNoRs, BY MESNE ASSIGNMENTS, 4ToCHICAGO HARDWARE FOUNDRY COMPANY, OF CHICAGO, ILLINOIS', A CORPORATIONoF ILLINOIS.l

INTERNAL-CYLINDE GRINDER.

Application tiled July 12, 1924.` Serial No. 725,573.

This invention relates generally to internal grinding devices and inparticular to a portable device for grinding the cylinders of internalcombustion engines.

Other devices in this art have long been employed, but the structuresthereof have been inadequate for exact grinding work because o f certaindeficiencies. Many prior devices have a plurality of movable arcuate l0abrasive members which are rotated or reciprocated within a cylinder tobe ground. Some of these are adjustable to vary the diameter, but nomeans is provided for maintaining these members at all diameters axiallyparallel. It has commonly been the practice to use the cylinder walls`being ground as the guiding means for these mem.

bers. lThis practice obviously maintains or exaggerates Certain originaldefects in the work. Other types of devices, however, have been providedwhich have a cylindrical grinding element, and hence this type overcomesthe deficiencies above set forth for the other types, but the cylinderelements heretofore provided are not equipped with adjusting means tovaryv the diameter of the grinder. f

It is an object of the invention to provide a cylinder grinder having atall times abrasive surfaces which are axially parallelv to the axis ofthe grinder irrespective of the walls of the cylinder being ground.

It is another Object to provide a grinder having a cylindrical abrasivesurface which vantages of the invention will become ap.

parent from the following description of an exemplaryy embodiment of theinvention which is shown in the accompanying Idrawings. The device ofthe drawings is a mechanism by which axially parallel grinding surfaces'are maintained, and in which 'is capable of size variation foradjustment.

the abrasive element is a single continuous abrasive surface, but it isto be understood that various other embodiments are contemplated by theinvention as will more fully appearhereinafter.

In the drawings, Figure 1 represents a longitudinal section ofthe deviceas viewed along the line 1-1 of Fig. 2.

Fig. 2 shows a cross 'sectional View along the line2-2 of Fig. 1.

Fig. 3 is across sectional line 3 3 of Fig. 1.

The device illustrated comprises a main shaft 10.Which carries thegrinding device. A suitable universal joint 11 is provided on the shaftthrough which a reciprocating and rotary motion` is transmitted to thedevice as a whole. A plurality of longitudinal members Orbars 12 ismounted on the shaft for parallel motion radially toward and away fromthe shaft in'order to effect a change in the diameter of thedevice. Itis the generall object of the invention to provide these longitudinalmembers with an abrasive carrying means substantially rigid therewith,to provide means for adjustlng the diameter of the device, and toprovide suitable resilient means co-operating with the adjusting means.

As a means for maintaining the longituviewalong the dinal members 12radially movable in parallel relationship to the axis of the grinder, aparallelogram linkage is provided for each member 12. In the presentinstance four such members are provided. Collars 13 and 14 are providedat spaced points on the shaft 10 and'are rigidly secured thereto bysuitable means as the in 15 for collar 13 which maintains it fixe ly onthe shaft, and as nuts 16 and 17 threaded onto shaft 10 for imaintaining collar 14.- adjustably fixed.

Suitable projections or lugs 18 are provided radially of the collars aspivot joints for the parallelogram linkage. The projections herein shownare formed by cutting four rectangular V-notches 19 into an enlargedportion 20 of the collars 14 and 15, thereby providing the projections18 with parallel side faces through which pass the pivotal pins 21herein shown as screws. The two faces of each of the projections' 18 areflanked by `short parallel links 22and 23 which extend to thelongitudinal members 12, the upper and lower sets of links beingmutually parallel. Pivotal pins 24 are shown connecting each member 12with each pair of links 22 and 23. By this construction eachmember 12becomes radially movable with respect to the shaft 10, is at all timesparallel thereto and is rigidly mounted against lateral deviation fromthe fixed radial line.

A suitable expansion mechanism is next provided. Internal lugs orprojections 26 are formed on each member 12, there being beveledsurfaces 27 on each lug. A bored tapering element in the shape of aconical frustum 28 is axially movable on the shaft 1() as a cam, actingon the beveled surfaces 27 of the lugs 26. The shaft 1() isscrewthreaded at 29 and is provided with a nut 30 which movesthe cone tomove the members 12 radially. A lock nut 31 is also provided on theshaft. /Tbe nuts 30 and 31 are of specially `large diameter and areknurled for easy manual manipulation. The lock nut 31- is provided withvery loose fitting threads which will permit the nut to rock slightlywhen positioned on the threads of the shaft 10. A thumb screw32 near theperiphery of the nut 31 locks the two nuts more firmly together vthanthe merev manual locking effect which may be obtained by tightening nut31 onto nut 30.

Suitable spring means is then provided tending to contract the membersradially against the cam action ofthe movable cone. By providing each ofthe members 12 with a suitable arcuate abrasive surface the grinder-iscompleted. In the present instance the arcuate abrasive surface andthespring acting means are-contained in a single member by the provision ofa resilient and radially expansible cylinder.v A steel cylinder 33withaIsubstantially longitudinal slot 34 therein is placed about the members12. Radial expansion of the members 12 is resisted by the resiliency ofthe cylinder. One of the members 12 is provided with pins 35 .which fitinto corresponding holes 36 in' the cylinder 33 to maintain it rigidlyfixed longitudinal of the device. A screw 37 Vthrough the cylinder intothe bar holds the cylinder thereon against accidental springmg away fromthe bar. A number of pairs of holes 36 may be provided to effect avariation of the position of the cylinder on the members 12 in whichcase the corresponding screw holes 38 in the bar are provided VVfor thescrew 37.

An abrasive cloth 39'is used about the cylinder.' For suitably securingthe cloth thereto a strip 40 is held inside the cylinder by screws 41entered into the outside face thereof. The edge 42 of the cloth 39 isclamped between the cylinder and the strip and the cloth then wrappedabout the cylinder. The other edge 43 may be left free either within .avery slight adjustment.

or without the cylinder according to its length, there being nonecessity to clamp or tighten it if the device is rotating in thedirection of the arrow in F ig. 2.

The device is specially designed for being mounted upon and vopera-tedby a portable motor, as for example, one used for handelectric drills. Aquickly detachable coupling is therefore provided. Above the univeisaljoint 11 is a driving shaft 44 which is operated by the electric drillor other power means. The universal joint 11 has vits upper member 45provided with screw threaded head 4G having projections 47 thereondiametrically disposed adjacent the periphery. The shaft 44 has a. disk48 at its end with a dianietrically disposed groove inder which isexpanded to fit into the automobile cylinder to be ground. The device asa whole is then inserted into the cylinder and further expanded until itgrips the same sufficiently to support itself. This adjustment iseffected by screwing nut 30 to move .the cone 28 toward the bottom ofthe device in such manner that the radial expansion of the parallel barstakes place. The nut 31 -is then screwed to lock nut 30 into positionand the screw 32 is used to bind the nuts 30 and 31 more effectivelyin'locked position. This arrangement serves in coopera-l tion with thecone 28 to lock the grinding mechanism in adjusted position, theresiliency of the cylinder exerting` pressure 1nwardly on the bars 12against the cone 28. After this adjustmentlhas been made the electricdrill or other power meansis connected and so operated as to rotate thewhole device within the cylinder the same being reciprocated axiallythereof manually or mechanically as may be required. When-required thedevice may be further expanded to increase the diameter slightly, andthus a feeding action may be secured `without removing the device fromnits operative position.

After longusafre the device may require It will be 0bserved that theupper ends of the bars 12 are held against contraction by the cone 28,thus relieving the upper set of links of considerable wear. No suchmeans is provided at the bottom set of links which therefore take all ofthe force of the lower ends, resulting in unequal wear between the upperand lower links. This tends to shorten the 'effective length of thelower links and may destroy the parallel relationship. However, by theprovision of the adjustably xed collar l5 this may be compensated for bya very slight adjustment which is insufficient to destroy the desirablerelationship of the linkage and the structure as above set forth.

The use of an expansible cylinder and the parallelogram linkages abovedescribed provides a grinding device having at all timesa-,substantially cylindrical abrasive surface. It will be observed thatin the expansion of the cylinder, the four radial bars 12 serve to bulgefour portions of the cylinder by pressing equally upon substantially theentire length of the spaced portions'of the cylinder. j

It is the ultimate object of the invention to produce a device of such acharacter that it may be inserted `into a cylinder and rotated, definingin its rotation a truly cylindrical path independently of any .guidingaction by the walls of the cylinder being ground. It is evident that thedevice herein described accomplishes this purpose by a simpleconstruction dependent, in the present instance, upon the employment ofthe simple parallelogram linkage -toeif'ect the proper movements of thebars toward and from the common' center, maintaining the parallelrelationship of the bars andthe axis of the device.A

To those skilled in the art it is apparent that other embodiments of theideas herein set forth are equally within the contemplation of Ithisinvention; In the appended claims it is our aim to setforth and definethe invention in its broadest scope limited only by the prior art.

We claim-as our invention:

l. An internal grinding device comprising, in combination, a centralshaft, two

spaced collars on said shaft, one collar being adjustable and the otherbeing fixed, a pluralityof parallel bars extending longitudinally ofsaid rshaft and being radially movable relatively thereto, a pluralityof links pivotally connecting said bars to said collars. a' coneadjustablymounted on said shaft and engaging said bars for adjustingsaid bars radially,and abrasive carrying means de- .ining a cylindricalsurface mounted on said bars. n

2. An internal grinding device comprising, in combination, a main shaft,a plurality of members mounted in parallel relationship to said shaftfor radial motion with respect thereto. a resilient cylinder having alongitudinal slit therein, saidl cylinder encircling said members andbeing substantially coextensive in length therewith, co-operating meansbetween one of said members and said cylinder to effect a rigid relationtherebetween, and means to expand said members radially to expand thecylinder against the resiliency thereof, said cylinder being adapted toreceive an abrasive material.

3. An internal grinding device comprising, in combination, a main shaft,a plural l combination, a cylindrical .abrasive-carrying member, saidmember being a resiliently and radially expansible. cylindrical device,and an expansion device carried within said cylindrical device, saidexpansion device comprising a plurality of parallel circularly disposedmembers extending substantially the length of the cylindrical device,and an expansion mechanism for said members, said cylindrical devicebeing associated with said expansion device, and anoperating meanscarrying the expansion device -and cylindrical device.

5. An internal grinder, having 1n combination, a cylindrically shapedabrasive carrying member, said member being radially eX- pansive, aplurality of parallel members within said cylinder extendingsubstantially the length thereof, means Auniformly to adjust saidmembers radially of the cylinder, means to hold the cylinder rigidlywith said members, and an operating shaft located, centrally of thecylinder for carrying said members.

6. An internal grinding device comprising, incombinatioma central shaft,two

spaced collars on said shaft, a plurality of radially movable membersparallel to said shaft, pivotal parallel links from each of said membersto said collars, means to adjust said members radially, uniformly. andsimultaneously with respect to said shaft, and anpexpansible cylindersurrounding said members and being adapted to carry an abrasivematerial. y

7. An internal grinding device compris; ing, in combination, a centralshaft, two spaced collars on said shaft. lugs on said collars, each lughaving parallel side faces, lugs on one collar being alined with thelugs on the other :collar parallel with the shaft, a plurality ofmembers radially movable with respect to the shaft, four parallelpivotal links from each member to one set of alined lugs, said linksflanking the parallel faces of said lugs. an abrasive-carryinerexpansive cylinder surrounding saidl members, and means simultaneouslyte adjust radially of the cylinder and nation, a shaft, a plurality ofbars adapt-edv to be moved toward and away from said shaft. parallellinks connecting each of said bars to said shaft, means for moving saidbars away from said shaft and for locking said bars in adjustedposition, and an expansible sleeve secured to one of said bars andadapted to be enlarged and loekedin adjusted position by said bars.

9. A cylinder grinder comprising. in combination. a shaft. a pluralityof bars. parallel links connecting said bars to said shaft, a .conemovable longitudinally upon said shaft and adapted to Contact With saidbars to more said bars awav from said shaft, a-

lock nut threaded on said shaft and adapted to abut said. Cone, a secondlock nut having a threaded bore slightly larger than the threadeddiameter of said shaft, and a movable screw carried by said second namedlock nut and adapted to bear against said.

10. A cylinder grinder comprising. in comv bin-ation, a resilientsubstantially cylindrical abrasive device. a plurality ofcircumferentially disposed parallel members arranged concentricallywithin said cylinder, and means to move said members radially withrespect to the common center, said members serving thereby to maintaincorresponding portions of the abrasive device in circumferentialrelation to said center.

In testimony whereof We have hereunto affixed our signatures.

LEO D. PANGBORN. ROGER-S M. iVARivICK. GEORGE H. MCKAY.

